The Slit-Scan Project: A Photo Finish

I saw this blog post by photographer James Guerin and was absolutely enraptured with what he achieved. He modified an old 35mm Pentax camera into a “slit-scan” camera and achieved some amazing images, many of which are featured in his blog.

You’ve seen “slit-scan” pictures before – horse racing fans will recognize the slit-scan images whenever a “photo finish” can determine a winner. Put one of those slit-scan cameras next to the finish line at a track and field event, and you can get some fantastic tape-breaking imagery.

Wow. The picture he created is freakin’ awesome. I wanna do that too. I wanna, I wanna, I wanna…

But before I wanna, I wanna figure out how to do it. In his blog, Guerin modified a Pentax 35mm camera and used several electronic wirings and gizmos to control the film advance. Unfortunately, I never learned how to solder or integrate wiring in such a manner as did he.

But I have an idea as to how I can create this image. And it involves my old Nikon EM.

I really haven’t used the EM for very much – a few star trail pictures now and again, but that’s about it. Most of the time it sits on the shelf, while my other 35mm shooter – my Nikon F100 – gets most of the action and use. But the EM was built with a manual hand-crank film rewind knob… so I have an idea.

I first cut a 1mm slit into a strip of black paper, and taped the paper inside the EM’s internal focal plane. Then I packed the camera with a roll of film, and advanced the film through the camera by “shooting” with the lens cap on. Once the film has been fully loaded, I simply activated the camera’s rewind mechanism, changed the camera’s shutter speed to “bulb,” and simply rewound the camera with the shutter open.

Wow… how in the world did I not think of this before?

Okay, camera’s modified for slit-scan use. I then took the camera over to a street in Latham and photographed some moving cars. As each car passed, I hand-cranked the winding knob on the EM. The camera remained mounted on a steady tripod. On a normal 24-exposure roll of cheap ISO 400 film, I was able to get four moving images.

Okay, I know this will work. You can see the horizontal stripes in the distance; that’s the stationary background while the film is moving at the same speed as the car.

I’m on the right track.

Track.

You know what? It’s time to go to the track.

But before I went to the track, I modified the camera some more. I also packed three rolls of cheap CVS 400 color film for my journey.

Let’s Go, Cardachrome – next stop, the Saratoga Race Course.

I set up my tripod along the rail, and carefully aligned my modified Nikon EM so that when the horses passed by, I could get a good photograph. I would only get three chances to do this – apparently races 1, 3 and 7 utilized Saratoga’s outer track; the other races were held on the inner turf tracks, out of range of my camera.

Okay. Let’s do this.

Each time the horses galloped by, I opened the camera shutter and hand-cranked the rewind knob on the EM.

And of the three races, this was the best shot I achieved. I wouldn’t call it “best” as much as I would call it “advancement.”

Now to take more notes. I’m getting the images, the execution is there, but there’s still some variables I have to manage. Obviously I’m cranking the controls too fast, as the film is passing through the shutter faster than the horses are arriving. Thus, the horses are still blurry. There’s at least one instance in this frame, however, where it looks as if I slowed down the hand-crank – and you can make out the front of one of the horses in the race. All the other horses look like they’re galloping at the speed of sound.

Gotta keep trying this. Can’t give up now.

I went back to the James Guerin photo for clues. According to the film codes, Guerin’s using Fuji ISO 100 film, and I’m sure he’s advancing that film at a much slower speed. Let me check my film stash for ISO 100 film. I’ve got one roll of Kodak Ektar 100 negative film, and two rolls of Kodak Elite Chrome 100 slide film. I then look at the schedule for Saratoga Race Course’s Sunday card. Races 1, 2, 3 are on the outer track, as are races 6 and 10. I’ll have five chances to make this work. All three rolls of film are placed in the camera bag.

I also packed two different lenses – my Nikon 50mm f/1.4 lens and my Nikon 85mm f/1.8 lens. Essentially I’ll have five chances to test my theory – three races with the Ektar and two with some Elite Chrome.

Oh yeah, and I gotta get some more money. Considering that the only thing I won at the track last Friday was a lot of sunburn…

It’s now Sunday morning. Apparently it’s “Blanket Day” at the Track, and as I travel from the Northway to Exit 14, I watched as hundreds of people at the Track carried dozens and dozens of red blankets out of the racetrack. Apparently the concept of “one per patron” was lost on many of them. Yes, yes, I know full well that part of the fun of going to the Track is performing the art of “turnstyling” and walking out with 15 hats or 10 umbrellas or 25 Tom Durkin bobbleheads…

No time for me to deal with blankets. I had to get to the rail before everyone else did, or else I wouldn’t have a good shooting location. Made it. Parked right near this hydrant.

No Standing on Hydrant Please. Photo by Chuck Miller.

With a roll of Kodak Ektar packed in the Nikon EM, I shot the first three races.

I then went into the “Carousel” clubhouse for some shade and hydration. I could feel my neck and arms aching. Great. There’s gonna be some sunburn in the morning. Never mind that. Photos now, Noxzema later.

I used up my Kodak Ektar on the three prior races; so I shot races 6 and 10 with the roll of Elite Chrome.

An anecdote – after the sixth race, as I went back to the Carousel for more shade and fluids, I saw what appeared to be a small family packing their things and preparing to leave the racetrack. The father of the group was furiously checking his pockets. “I thought I had the ticket for the blanket,” he grumbled. “I hope I didn’t lose it.”

A quick scan. None of the family possessed any of the promotional red coverlets.

“Here,” I said, reaching in my pocket for my blanket ticket and handing it to the man. “Take mine.”

The father thanked me, and he and his family headed over to redeem the ticket.

Now some of you are going to say to me, “Hey Chuck, that guy could have had twenty tickets in his pocket and you just gave him a twenty-first ticket. Dumb Chuck.”

And to you I say, “Hey look. Unless Capital Rep is holding auditions for a revival of You’re A Good Man, Charlie Brown, I really DON’T need a blanket. So big deal if I gave my ticket away. You’re just cheezed because I didn’t give the ticket to you.”

And with that, my modified camera and I headed home. No, I didn’t win any races at the Track. But hopefully I’ve got some winners in the Nikon EM.

Tuesday morning. Time to drop off some film at McGreevy Pro Lab.

Tuesday afternoon. McGreevy Pro Lab sends me an e-mail. Film is done.

I quickly scan the five images into my computer, and post the results on my flickr account.

In other words… I got the slit-scan project to work. Fist pump. Even the TU horse-betting staff might be pleasantly impressed in seeing these results.

Now for my next steps. If I do this again, I need to make sure I hook my EM to a telephoto lens, like maybe my 1960’s telephoto “Rachel” lens. I’m also going to have to find a way to attach a servo-motor to the rewind knob, because no matter how steady I think my cranking hand might be, you can still see white vertical lines where I either slowed down or sped up my crank-speed.

But the main thing is… I got this project to work. I built myself a photo-finish camera out of a Nikon EM and some good-old-fashioned ingenuity – as well as inspiration from a fellow photographer’s efforts. And now I’m going to refine this technique, improve on it, work with it… and eventually come up with an award-winning photograph.

What, you think I’m going to stop now?

Not a chance in the free world.

Chuck Miller

3 Responses

That mind of yours Chuck! I like races 3 and 10 the best – coloring is good for me to focus on. Great job! And that was nice of you to give that family your ticket. It would just be another thing to pack into one of those big garbage bags in a few years for drop off at the Salvation Army.